The full name of TR-90 is "Grilamid TR90". It was originally a transparent nylon material developed by the Swiss EMS company. Because of its various properties suitable for the production of mirror frames, it is widely used in the optical field (in fact, EMS company also has a kind called TR-55. , but its characteristics are not suitable for frame products). TR90 is the nylon 12 (PA12) of EMS company, which has the following advantages: 

1. Light weight: about half of the weight of the sheet metal frame, 85% of the nylon material, reducing the burden on the bridge of the nose and ears, making it more comfortable to wear.

2. Bright colors: more vivid colors than ordinary plastic frames.

3. Impact resistance: more than 2 times that of nylon material, ISO180/IC: >125kg/m2 elasticity, so as to effectively prevent eye damage caused by impact during sports.

4. High temperature resistance: It can withstand high temperature of 350 degrees in a short period of time, ISO527: anti-deformation index 620kg/cm2. Not easy to melt and burn. The frame is not easy to deform and not easy to change color, which makes the frame wear longer. 5. Safety: no chemical residue release, in line with European requirements for food-grade materials.